Method of screen printing



June 3, 1947. H. BUCKLIN I METHOD OF SCREEN PRINTING Filed Oct. 23, 1945 h wk III II I IIIHHIIIIII llllllllln l l l l I I I I II II III Patented June 3, 1947 2,421,410 METHOD or SCREEN PRINTING Herbert Bucklin, Sanford, Maine, assignor to Goodall-Sanford, Inc., Sanford, Maine, a corporation of Maine Application October 23, 1945, Serial No. 624,051

8 Claims.

This invention involves a novel method of screen printing to avoid juncture marking.

The screen printing of textiles is an old and familiar art in which colored patterns having regular repeats are printed by the use of a series of silk screens applied successively, one for each color, to the fabric and through which the color is pressed on to the fabric. That portion of the screen not employed in printing the particular color is blocked out, in the usual manner, so that the color does not pass through.

Where a color of such a pattern having regular repeats extends continuously between adjacent repeats great difficulty has hitherto been experienced by the appearance of marks transversely of the color where successive printings come together, and great care is required in all such cases to prevent such juncture marking. The flaws or imperfections in the printed fabric due to such juncture marking are particularly diflicult to avoid when, for example, the color of the back- 7 ground of the pattern extends continuously between adjacent repeats or when there is a stripe in the pattern the color of which consequently extends continuously between adjacent repeats.

It is the object of the present invention to prevent such juncture marking by the use of two screens printing the same color but difiering in the area printed.

The nature of the invention will appear more fully from the accompanyin description and drawings and will be particularly pointed out in the claims.

In the printing of fabrics by the screen printing process, the repeat of the pattern may, and ire quently does, involve a considerable number of different colors and the configuration of that portion of the pattern printed by each color may be, and often is, highly irregular. Such patterns may involve simple symmetrical designs, or for example, run to elaborate floral effects. But it will be sufficient for the purpose of illustrating the method of the present invention to assume an extremely simple form of pattern and the drawings therefore, illustrate such a simple pattern. In the first form there is illustrated a pattern in which each repeat comprises a circular blue spot, a square red spot and an irregular shaped red spot with a gray background. In the second form there is illustrated a continuous sinuous red stripe and a continuous straight blue stripe on a gray background. It will be seen that in the first form the color of the gray background and in the second form the two colors of the stripes extend continuously between adjacent repeats and consequently these colors, the color of the background in the first form and the color of the stripes in the second form, are particularly likely to show juncture marking. To avoid this it has been common, in the case of patterns of the first form, to vary the patterns so that there will be connecting elements extending transversely of the fabric thus preventing the color of the background extending continuously. And in the case of the second form it has been impractical commercially to print by the screen printing process such striped patterns perfectly.

In the drawings,

Fig. 1 represents a very simple pattern, as pointed out, with the regular repeats indicated at l, 2', and 3 in which there are the red and blue colored areas indicated and a gray background extending continuously between adjacent repeats.

Fig. 2 represents an example of the first screen employed and Fig, 3 the second screen employed for printing the background of a fabric such as illustrated in Fig. 1 by the method of this invention.

Fig. 4 represents another very simple pattern in which a sinuous red stripe and a straight blue stripe and. a gray background each extends continuously between adjacent repeats indicated again at l, 2, and 3.

Fig. 5 represents an example of the first screen employed and Fig. 6 the second screen employed for printing the red stripe of a fabric such as illustrated in Fig. 4, by the method of this invention.

Fig. 7 is a diagram for the purpose of illustrating one sequence of printing with screens of the type of Figs. 2 and 3.

8 is a diagram for the purpose of illustrating one sequence or printing with screens of the type of Figs. 5 and 6.

Referring first to Figs. 1, 2, and 3 there is illustrated in Fig. 1 a portion of a strip of fabric 10 upon which there is printed a gray background and an irregular pattern with separated elements. This pattern may be printed with any desired number of colors and may be either of a simple or of a very elaborate character. But it is sufficient, for the present purpose, to consider the pattern as printed with two colors, the square figure at H being printed with red, the circular figure I2 and the irregular figure l3 being printed in blue. The pattern repeats through the length of the fabric regularly and the repeats are indicated at the right-hand margin of the figure marked 1, 2, 3, 4. It is assumed that the pattern in the various colors with the exception of the background has been printed or is printed progressively by the required silk screens in the usual manner.

In the present case it will be seen that the background extends continuously between successive repeats and the invention is concerned with the printing of this background so as to avoid the appearance: of juncture markings.

For this purpose there are prepared two screens for the color of the background and a preferred character of these screens is illustrated in Figs.2 and 3. In each of these screens the portions of the pattern other than the background are rendered imperforate to the background color in the usual manner and these areas are, therefore, shown in black.

The first screen illustrated in Fig. 2 contains the entire repeat of the background color in the portion indicated at I4 and also contains an irregular end section of the preceding repeat, this being the remaining portion indicated and bounded bythe-irregularline [5 which extends in any desired manner, preferably from one element toanot-herof the pattern elements ll, I2 and I3.

The second screen illustrated in Fig. 3 containsthe entire repeat of the color of thebackgroundwith the exception of an irregular end section similar to that at the front of the first screen. In other words, the portion at the front of the first screen which will extend over a preceding repeat is omitted from the end ofthesecond screen, the line I6 bounding the end of the secondscreen being the same as the line I5.

The background of the fabric is then printed by: applyingand printing with both of the screens to printthe end section of each repeat once with the endsection of the first screen, once with the end section of thesecond screen and once with the'front section of the first screen and the remaining-front section of the repeat once with each screen, thusprinting with the two screens the entire repeat twice. While printing it is necessary that the colorsapplied by the screens shall be in condition to blend and for this purpose the colors must be suitably treated. For example, it is common -in silkscreen printing to include in the printing paste about 1% of turpentine and it has been found that the proper blending ofthe colors maybe effected in the present case by employing substantially 12% of turpentine.

The particular order in which the two screens are applied when of the type shown in Figs. 2 and 3 may be varied but it has been found desirable to'apply and print with the screens in the order indicated in the diagram of Fig. 7 where the repeats are indicated at I, 2, and 3, the first screen at H and the second screen at l8. In this diagram the order of application of the screens is indicated by their lateral position. As indicated by this diagram, the first screen H is first applied thus printing the repeat l and the end section of the preceding repeat. The first screen is again applied this time to the third repeat thus printing that repeat and the end section of the second repeat. The second screen I8is then applied to the second repeat printing that repeat except for the portion of the end section printed by the first screen. The second screen [8 is'then applied to the first repeat printing that repeat with the exception of the irregular end section. The first screen I! is then applied to the second repeat printing that repeat and the portion of the end section of the first repeat not printed by the second-screen. The second screen [8 is then applied to the third repeat printing that repeat with the exception of the irregular end section and the printing so continued. It will thus be seen that the entire repeat in each case is printed twice, the front portion of the repeat being printed once by each screen while the end portion of each repeat is printed twice by the first screen and once by the second screen.

Referring nowto Figs. 4, 5, and 6 there is illustrated a' strip of fabric i9 also having repeatsindicated at the right-hand margin i, 2, 3, and

4. In this pattern it is assumed that the main pattern itself contains one or more color patterns extending "continuously between adjacent repeats as in the case of stripes. For this purpose there'is indicated a stright blue stripe 20 and a sinuous red stripe 2!. The pattern may, of course, contain other colors and designs all printed in the usual manner. The background in the illustration also extends continuously between adjacent repeats and would be printed in'accordance with themethod already described. Each stripe, such as 26 and El, is also printed by the method of this invention, and it will be sumcient to describe the printing of the sinuousred stripe 2!.

For this purpose there are prepared two screens illustrated respectively in Figs. 5 and 6. The first screen shown in Fig. 5- contains the entire repeat of the-color, the remaining portion of the screen being rendered impenetrable bythe color as indicated black. The second screen, as shown inFig; 6, contains a transverse front section of the repeat of the color anda-complementary transverse end section of the preceding repeat. That is, for example, it is the length of a repeat but-covers the area between the lines 6-6 of Fig. l.

The stripe is then printed by applying and printingwith each of thesetwo screens toprint each frontsection and each end section of each repeat twice and while, asbefore, the colors applied are. in condition to blend. Preferably the two screens are applied and. printed Within regular'alternation-as indicated in the diagram of .Fig.-8 where-thefirst screen containing the entire repeat is indicated at 22 and the second screen containing a transverse front-section -of the repeat and a complementary transverse end section of the preceding repeat is indicated at 23.

A somewhat similar principle-may also beemployed in printing fabrics of the type illustrated in Fig. 1 whereever it is practical to find a straight transverse end section of the repeat of the color. In such case the first screen would contain the entire repeat together with a front section corresponding to the transverse end section of the preceding repeat while the second screen would contain the entire repeat with the exception of a similar transverse end section. Consequently in printing with the two screens, the front section of each repeat would be printed once with each screen and the end section once with the endse'ction and once with the front section of the first screen thus the entire repeat being printed twice.

Having thus described the inventiom what is claimed as new and desired to be secured by Letters Patent is:

1. The method of screen printing to avoid juncture marking in a color of a pattern'having regular repeats in which the color extends continuously between adjacent-repeats which consists inpreparing two screens for the said color,

one screen including the entire repeat of the color, the second screen including the front section of the repeat of the color, the two screens being placeable the one on one, and the other on the other, of adjacent repeats to include overlapping sections within the said overlapping sections together covering at least once the end section of the first repeat, applying and printing with both screens each repeat to print each front section and each end section of each repeat twice and while the colors applied are in condition to blend.

2. The method of screen printing to avoid juncture marking in a color of a pattern having regular repeats in which the color extends continuously between adjacent repeats which consists in preparing two screens for the said color, one screen containing the entire repeat of the color and an irregular end section of the preceding repeat, the second screen containing the entire repeat of the color with the exception of a similar irregular end section, applying and printing with both screens to print the end section of each repeat once with the end section of the first screen, once with the end section of the second screen and once with the front section of the first screen, and the remaining front section of the repeat once with each screen, thus printing with the two screens the entire repeat twice, and printing in each case while the colors applied are in condition to blend.

3. The method of screen printing to avoid juncture marking in a color of a pattern having regular repeats in which the color extends continuously between adjacent repeats which consists in preparing two screens for the said color, one screen containing the entire repeat of the color and an irregular end section of the preceding repeat, the second screen containing the entire repeat of the color with the exception of a similar irregular end section, applying and printing with both screens to print the front section of each repeat once with each screen and the end section of each repeat once with the front section and once with the end section of the first screen and once with the end section of the second screen whereby the entire repeat is printed twice, and printing with the screens while the colors applied are in condition to blend.

4. The method of screen printing to avoid juncture marking in a color of a, pattern having regular repeats in which the color extends continuously between adjacent repeats which consists in preparing two screens for the said color, one screen containing the entire repeat of the color and an irregular end section of the preceding repeat, the second screen containing the entire repeat of the color with the exception of a similar irregular end section, applying and printing a repeat and the end section of the preceding repeat with the first screen, applying and printing the front section and a portion of the end section of the first repeat with the second screen, applying and printing the second repeat and the remainder of the end section of the first repeat with the first screen and continuing the printing with the two screens to print the front section of each repeat once with each screen and the end section twice with the first screen and once with the second screen, and so printing while the colors applied are in condition to blend.

5. The method of screen printing to avoid juncture marking in a color of a pattern having regular repeats in which the color extends continuously between adjacent repeats which consists in preparing two screens for the said color, one screen containing the entire repeat of the color and an irregular end section of the preceding repeat, the second screen containing the entire repeat of the color with the exception of a similar irregular end section, applying and printing the first repeat with the first screen, the third repeat with the first screen, the second repeat with the second screen, the first repeat With the second screen, the second repeat with the first screen, the third repeat with the second screen and so continuing printing with the two screens in each case while the colors applied are in condition to blend.

6. The method of screen printing to avoid juncture marking in a color of a pattern having regular repeats in which the color extends continuously between adjacent repeats which consists in preparing two screens for the said color, one screen containing the entire repeat of the color, the second screen containing a transverse front section of the repeat of the color and a complementary transverse end section of the preceding repeat of the color, applying and printing with each screen to print each front section and each end section of each repeat twice and while the colors applied are in condition to blend.

7. The method of screen printing for the purpose and as defined in claim 6 in which the two screens are applied and printed with in regular alteration.

8. The method of screen printing to avoid juncture marking in a color of a pattern having regular repeats in which the color extends continuously between adjacent repeats which consists in preparing two screens for the said color, 50 one screen containing the entire repeat of the color and a transverse end section of the preceding repeat, the second screen containing the entire repeat of the color with the exception of a similar transverse end section, applying and 55 printing with both screens to print the front section of each repeat once with each screen and the end section of each repeat once with the front section and once with the end section of the first screen thus to print the entire repeat 60 twice, and printing with the screens while the colors applied are in condition to blend.

HERBERT BUCKLIN. 

